太赫兹频段复杂目标雷达散射截面测量与验证

国防科技大学电子科学学院,湖南长沙 410073

电子技术; 雷达散射截面; 太赫兹雷达; 测量系统; 微波倍频; 复杂结构; 电大尺寸目标

Measurement and verification of radar cross section of complex targets in terahertz frequency band
PANG Shuang, ZENG Yang, YANG Qi, LI Yanpeng, DENG Bin, and WANG Hongqiang

College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, Hunan Province, P.R.China

electronic technique; radar cross section; terahertz radar; measurement system; microwave frequency multiplication; complex structure; electrically large object

DOI: 10.3724/SP.J.1249.2019.02170

备注

针对太赫兹频段范围内对复杂目标的雷达散射截面(radar cross section, RCS)测量存在系统信噪比低,测量精度低,测量能力难以满足需求; 复杂目标RCS理论求解困难,测量数据分析缺乏理论支撑,难以有效评估测量结果及系统性能问题,搭建一个基于矢量网络分析仪的微波倍频太赫兹RCS测量系统,该系统可以产生多个频段的太赫兹波,实现多频段复用.该系统的信号在频率、幅值和相位上具有较好的稳定性,有望提高RCS的测量精度.利用该系统对复杂目标模型(吉普车和卫星)在220 GHz和440 GHz频段下进行测量(方位角0°~360°,俯仰角0°),并采用不同方法(与计算值比对、计算模型对称部位测量值差值)对系统测量性能进行分析验证.结果表明,该系统能够在太赫兹频段实现对复杂目标散射特性的测量,可用于太赫兹雷达系统及太赫兹频段缩比测量的研究.

Radar cross section(RCS)measurement of complex models in terahertz band is considered challenge mainly owing to the following two reasons. One is the low signal to noise ratio(SNR)of measurement system, which limits the measurement accuracy. The other is the difficulty in calculating RCS values for complex models, which makes it hard to evaluate the measurement results and the performance of the system. To overcome these problems, we construct a multiband terahertz RCS measurement system based on a vector network analyzer. The signal of the system has good stability in frequency, amplitude and phase, which leads to improvement in RCS measurement accuracy. Based on the system, we measure RCS of complex target models(jeep and satellite)at 220 GHz and 440 GHz(with azimuth angle of 0°~360°, pitching angle of 0°)and use different methods to evaluate the performance of the system. The methods refer to comparing measurement results with computing values and calculating the difference of measurement results between symmetrical parts of the model. The results show that the system is capable of measuring the scattering characteristics of complex targets in terahertz band with high precision. The system is of great value for the development of terahertz radar system and the research of RCS scaling measurement.

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